This invention relates to flexible lip seals. More particularly it relates to lip seals which can accomodate significant shaft-to-bore misalignment or dynamic runout.
Lip seals are molded of of an elastomeric or polymeric material and surround a rotating shaft in sealing relationship to provide a fluid or gas tight chamber in a housing from which the shaft extends. Such seals embody components or elements including a retainer to aid installation, withdrawal and retention of a seal body relative to a housing; and one or more elastomeric or polytetrafluorethylene sealing lips.
The lip seals of the present invention are particularly suited for, but not limited to, use in conjunction with automotive air conditioning compressors. This type of service is particularly severe. The refrigerant to be sealed usually has a deliterious effect on elastomeric and other seal materials. The pressure ranges, from vacuum to high, and the temperature ranges are extreme.
In addition, the economies of automobile production require constant effort to reduce weight and cost. Equipment design tends toward light weight or duty. The result is that seals must accomodate more extreme specifications in terms of permissible misalignment between shaft and bore and also dynamic runout.
The seal of the present invention utilizes a unitary seal body having several sealing lips. Previous lip seals have utilized separate seal body components requiring assembly. These prior designs pose several potential problems, including improper installation of seal components, missing seal components, improper axial compression of seal components and a set internal gasket compression. Often, one or more of these problems conspire to result in internal leakage through the assembled seal.
The seal of the present invention provides a solution to these problems.